Problem: On Saturday, Umaima's parents gave birth to twins and named them Stephanie and Ishaan. When they were first born, Stephanie weighed 8.67 pounds and was 19.5 inches tall, and Ishaan weighed 7.81 pounds. How much did the babies weigh in total?
Explanation: To find the weights of the 2 babies, we need to add their weights together. Stephanie's weight + Ishaan's weight = total weight. ${8}$ ${6}$ ${7}$ ${7}$ ${8}$ ${1}$ ${+\vphantom{0}}$ ${8}$ ${4}$ ${6}$ ${1}$ Together, the babies weigh 16.48 pounds.